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Welding on a small air compressor tank . . .

I have a smallish air compressor pump I rebuilt, and just picked up a tank (DeVilbis) that had a dead compressor on it. I need to weld an additional pad on the top of the tank to take my motor. Any special precautions needed for welding to a 150psi rated tank? I'm guessing 1/8" E6013 or E7018, since they don't dig much, and low amps, and short-spaced and/or back-stepped beads not more than a couple of inches long. Can I reduce any introduced stresses with a little pre-heat? A burst compressor-tank can knock a wall right out of your garage!

well if it was mine i would trash the 6013's if you have 7018's,you say you need to weld a pad on i would just drag me a nice bead around it...make sure your heat is right before you start & open a valve on the tank so it can breath,,,make sure >NO< undercut or you have a chance for problems...this is just what i have done in the past with excellent results...6013 is an alright rod BUT if you have 7018's why waste your time with 6013...

I have welded on lots of them over the years and one is still in my basement and i use it daily. But that was before i knew the rules or codes on welding on pressure vessels and how they should be done right. Someday i am going to cut mine up so no one ever gets hurt after i pass off this earth because it has to be pushing 40 years old...Bob

I think with some enginuity you should be able to construct a mount bracket that bolts to the existing motor mount & a band to support it somehow would be the way to go. I would back away from the weld idea. If you can post some pics it would give me a better way of describing how to make the mounting bracket.

I have a smallish air compressor pump I rebuilt, and just picked up a tank (DeVilbis) that had a dead compressor on it. I need to weld an additional pad on the top of the tank to take my motor. Any special precautions needed for welding to a 150psi rated tank? I'm guessing 1/8" E6013 or E7018, since they don't dig much, and low amps, and short-spaced and/or back-stepped beads not more than a couple of inches long. Can I reduce any introduced stresses with a little pre-heat? A burst compressor-tank can knock a wall right out of your garage!

And big chunks of metal can go flying like a grenade.
We have a thread or two about this stuff somewhere. With pics!
If you are SMART you won't do it. Unless maybe you build a cage around it like they have for mounting split rim truck tires.

One of the things that bothers me about this is the experience of having cut up an old rusty tank; dismayingly thinwall construction. Yet I also once was shown a tank repair done by a long-time owner of a compressor sales and repair shop. I forget now whether he said it was a crack or a hole in the side of that small tank, but he had done a pretty rough looking brazing job over the top of it. I declined to buy his tank, but his assurance that it was fine made me think that they must be less critical than I had assumed. Still, my inclination is to be conservative when I don't KNOW and can only guess.

I could ask you what steel is customarily used for these tanks, but that probably varies depending on whether the tank was built here or is constructed of Chinese mystery metal. One positive sign is that this tank feels considerably heavier than others I've lifted.

I mentioned E6013 only as an example of a rod that doesn't penetrate as much as some, and I personally haven't run any of it in decades. If I were to weld on this tank, I'd use E7018, 3/32" rather than 1/8". But since I don't know what I'm doing, Sundown, and since I haven't yet been told how to do it successfully, I suppose I won't.

The existing pad is awfully small for cantilevering much structure off one end to support a heavy weight. I guess what I could do is make a pad that I can strap to the tank with a couple of home-made band-clamps. Or just look for another tank.

doing the strap thing would be just wrong...if you can weld then 7018 3/32 rod will work & if your scared then get someone that can weld to do it,no need in wasting this tank...IT CAN BE DONE & is done everyday...i told you how to do it....